Noninterflow rotary valve and improved fluid seals

ABSTRACT

A housing has upper and lower pressure chambers separated by a housing central portion, each chamber containing a pivotal rotor adjacent the central portion. The housing central portion has first and second ports, each opening into both chambers against the rotors, a third port opening only into the upper chamber and a fourth port opening only into the lower chamber. Each rotor has two ports therethrough so that in alternate positions, the upper rotor ports communicate with the central portion third port and alternately with the central portion first and second ports, while the lower rotor ports communicate with the central portion fourth port and alternately with the central portion second and first ports. The rotors are connected simultaneously pivotal and spool seals are mounted in the ends of the central portion ports against the rotors permitting such rotor pivoting.

United States Patent 5/l883 Wilson 1.990.423 2/ l 935 BohneblustABSTRACT: A housing has upper and lower pressure chambers separated by ahousing central portion, each chamber containing a pivotal rotoradjacent the central portion. The housing central portion has first andsecond ports, each opening into both chambers against the rotors, athird port opening only into the upper chamber and a fourth port openingonly into the lower chamber. Each rotor has two ports therethrough sothat in alternate positions, the upper rotor ports communicate with thecentral portion third port and alternately with the central portionfirst and second ports, while the lower rotor ports communicate with thecentral portion fourth port and alternately with the central portionsecond and first ports. The rotors are connected simultaneously pivotaland spool seals are mounted in the ends of the central portion portsagainst the rotors permitting such rotor pivoting.

ROTARY VALVE AND IMPROVED FLUID SEALS NONINTERFLOW BACKGROUND or THEINVENTION v twopressure chambers, each having a flow controlling rotortherein, said chambersand rotors being constructed such that it isunnecessary to either increase the valve size or reduce the valve portsize in order to obtain optimum noninterflow characteristics. As anadded feature of the present invention, unique forms of spool-type sealsare provided in the rotary valve between ports of a stationary valvehousing and the pivotal valve rotors, again increasing the valvenoninterflow characteristics made possible by the foregoing dualpressure chamber concept;

. In modern technology and industry, it has been along sought aftergoalto provide a rotary valve having controlled dual fluid stream flowtherethrough with true noninterflow characteristics, yet withoutincreasing the valve size or reducing the flow capacity thereofappreciably from prior rotary valves not having such noninterflowcharacteristics. As an example, assume'a rotary valve having an inletport and an outlet port along with two separate working ports and hisdesired to alternate the fluid flow of two fluid streams, one enteringthe inlet port and the other exiting the outlet port, between the twoworking ports, that is, in one valve position, the inlet port would beconnected to the first working port and the outlet port would beconnected to the second working port, while in another valve position,the inlet port would be connected to the second working port and theoutlet port would be connected to the first working port. Furthermore,assume that during a particular valve position, it is desired to provideminimum interrnixing between the two fluid flow streams and moreimportant, to minimize such stream interrnixing, as well as minimizefluid pressure loss within the valve, during the valve movement betweenits two positions. i

An application forsuch a noninterflow valve might'be for the controllingof pressure fluid inlet and exhaust to and from a double acting, fluidactuated cylinder necessary to act in its opposite stroke movements in avery precise and exact, predetermined manner, without any appreciablevariation. In such application, the rotary valve working ports would becon nected to the opposite ends of the fluid cylinder with the rotaryvalve alternate positioning alternately supplying fluid to andexhausting fluid from the cylinder ends. If the rotary valve controllingthe fluid cylinder does not have excellent noninterflow characteristics,intermixing of the fluid flow streams or pressure losses within thevalve can result in the movements of the fluid cylinder being erraticand unpredictable.

Prior to the present invention, where noninterflow characteristics areof importance, the problem has been satisfied by either making use oftwo separate rotary valves for the single application or greatlyincreasing the size of a single rotary valve. In the case of the twoseparate rotary valves, each can be of sufficient size and capacity sothat the various ports thereof maybe separated sufiicient distances thatthe controlling movable rotors will completely close ports previouslycommunicated with prior to opening other ports for the al-.

ternate fluid flow streams therethrough. in the case of a single rotaryvalve, the prior constructions have been increased in size for the samepurpose, that is, to separate the various ports thereof sufficientlythat the single movable rotor may move the rotor ports completely awayfrom those ports previously communicated therewith to close the sameprior to establishing communication with other ports to alternate theflow streams in the manner discussed.

t, Another required characteristic ofnoninterflow rotary valvesimportant of consideration where absolute optimum noninterflowcharacteristics are desired is the construction of fluid seals betweenthe ports of the stationary rotary valve housing and the ports of thepivotal rotors thereof. if interflow between the fluid streams is to bereduced to an absolute minimum so as to be virtually eliminated,particularly under high fluid pressure conditions, such seals must haveexcellent sealing characteristics, while still permitting the relativemovement between the valve housings and rotors. Prior to the presentinvention, the sealing characteristics of the rotary valve seals havebeen quite lacking and troublesome, either engaging the valve parts withsuch high force so as to make the valve movements extremely difficult orengaging the valve partswith such a minimum force that fluid interflowis not prevented.

OBJECTS AND SUMMARY or THE INVENTION 1. It is, therefore, an object ofthis invention to provide a rotary valve adapted for simultaneouslytransmitting two fluid flow streams there'through and switching saidstreams between various thereof ,wherein stream interflow within saidvalve and pressure loss of said streams is greatly minimized, if notvirtually completelyeliminated. The basic concept of the valve includesthe provision of a single stationary housing portion between twoseparate pressure chambers, each chamber having a separate controllingrotor therein. The housing and rotor ports directing the separate fluidstreams through the valve are arranged so that only one fluid streamflows through each of the pressure chambers in a given position of thevalve, alternate positioning of the valve either redirecting each ofsaid fluid streams through the same pressure chambers or, morepreferably, switching the direction of individual stream flow to theother pressure chamber.

It is a further object of this invention to provide a rotary valvehaving the foregoing general characteristics and can struction whereinthe valve stationary housing may be provided with a single pressure orinlet port through which there is always fluid inflow, a single exhaustor outlet port from which there is always fluid outflow, and two workingports which are alternately fluid inflow and outflow ports, said lattertwo working ports being those connected to a working mechanismcontrolled by the rotary valve. Further in the preferred form, the inletand outlet ports of the rotary valve are connected to each of thepressure chambers and the two working ports are connected to one each ofthe pressure chambers. The individual rotors may. have the ports thereofarranged so that movement of. that particular rotor to one position willconnect its connected working port to either the inlet or outlet port,and in another rotor position will connect its connected working port tothe other of the inlet and outlet ports. Thus, by providing properrelative positioning between the two rotors of the two pressurechambers, it is possible to direct separate fluid streams separatelythrough the pressure chambers in one position of the rotary valve andswitch the direction of each fluid stream to the other or opposite ofthe pressure chambers in another position of the rotary valve.

It is still a further object of this invention to provide a rotary valvehaving true noninterflow characteristics without the necessity ofincreasing the valve size for a given flow capacity, or without thenecessity of reducing the valve port size to thereby reduce the flowcapacity thereof for a given overall valve size. By the use of twoseparate pressure chambers, each having a flow controlling rotortherein, said separate pressure chambers being arranged spaced about asingle port containing stationary valve housing, it is possible toprovide suflicient housing and rotor port spacing and separation so thatat least certain of the ports may be completely closed prior toreopening or opening other ports between alternate positions of thevalve. in this manner, fluid flow through the ports is completelyblocked by the rotors to not only effectively prevent fluid streaminterflow, but also to prevent pressure drops in the fluid streamsnormally resulting from such interflow and other fluid leakage. Again inthe preferred form of the rotary valve, the two rotors for the pressurechambers are preferably simultaneously movable and the relativelocations of the housing and rotor ports are such that all housing portsare effectively blocked for an interval between flow communicatingpositions of the rotors, resulting in maximum noninterflowcharacteristics despite the simultaneous fluid flow control of two fluidstreams through the rotary valve.

It is an additional object of this invention to provide a rotary valvewhich may include parts or all of the foregoing advantageouscharacteristics and construction, and may further include unique formsof spool-type seals engaged between the valve stationary housing and thevalve rotors producing extremely effective fluid seals for optimumnoninterflow characteristics while still permitting ease of pivotalmovement and positioning of the valve rotors. In the preferred form ofthe rotary valve of the present invention, the spool-type seals arepreferably mounted in annular recesses surrounding the stationaryhousing ports urged axially into abutment with radial surfaces of therotors and having resilient sealing rings arranged therein for maximumscaling in particular directions of fluid flow dependent on the moreimportant fluid flow direction to or from that particular port. Theunique spooltype seals included in the preferred form of rotary valve ofthe pr :sent invention may also have advantageous use and application invarious other types of valves and fluid flow devices wherein fluid flowstreams are directed between ports of adjacent members, and particularlywhere it is necessary to provide relative movement between said memberswhile maintaining said port sealing Other objects and advantages of theinvention will be apparent from the following specification and theaccompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of apreferred embodiment of a rotary valve incorporating the principles ofthe present invention;

FIG. 2 is an enlarged, vertical sectional view looking in the directionof the arrows 2-2 in FIG. 1;

FIG. 3 is an enlarged, fragmentary, vertical sectional view taken fromFIG. 2 and showing one form of spool-type seal of the present invention;

FIG. 4 is a view similar to FIG. 3 but showing another form ofspool-type seal of the present invention;

FIG. 5 is a reduced, horizontal sectional view looking in the directionof the arrows 5-5 in FIG. 2;

FIG. 6 is a reduced, horizontal sectional view looking in the directionof the arrows 6-6 in FIG. 2;

FIG. 7 is a reduced, horizontal sectional view looking in the directionof the arrows 7-7 in FIG. 2;

FIG. 8 is a reduced, horizontal sectional view looking in the directionof the arrows 8-8 in FIG. 2; and

FIG. 9 is a fragmentary, vertical sectional view looking in thedirection of the arrows 9-9 in FIG. 2 and showing certain of the valvehousing fluid flow ports in hidden lines and certain other of saidhousing ports in phantom lines to illustrate the relative positioningthereof.

A preferred embodiment of rotary valve including the principles of thepresent invention is shown in the drawings and includes a generallycylindrical, stationary housing generally indicated at It) formed by acentral housing portion l2 axially spacing or separating upper and lowerhousing portions 14 and 16, all of said housing portions preferablybeing formed of stainless steel or the like with the upper and lowerhousing portions being secured to the central housing portion by aseries of appropriate fasteners 18. Generally cylindrical pressurechambers 20 and 22 are formed in the upper and lower housing portions 14and 16, the upper pressure chamber being substantially identical to thelower pressure chamber except axially reverse and each being enclosed byits respective upper or lower housing portion with the exception ofopening axially against the central housing portion 12. A centrallylocated positioning shaft 24 is received axially through the centralhousing portion 12 extending downwardly into the lower pressure chamber22 and upwardly through both of the upper pressure chamber 20 and theupper housing portion 14.

A generally cylindrical upper rotor 26 is positioned in the upperpressure chamber 20 substantially radially spanning said upper pressurechamber with a lower surface 28 thereof axially adjacent the centralhousing portion 12, and a similar lower rotor 30 is similarly positionedin the lower pressure chamber 22 with an upper surface 32 adjacent thecentral housing portion. The upper and lower rotors 26 and 30 receivethe positioning shaft 24 axially therethrough and are appropriatelykeyed to the positioning shaft for rotatable or pivotal movementtherewith. Furthermore, thrust bearings 34 are mounted in the centralhousing portion 12 axially abutting the upper rotor lower surface 28 andthe lower rotor upper surface 32, the upper rotor 26 being retaineddownwardly against the upper of the thrust bearings 34 by a shaft collar36 and the lower rotor 30 being retained upwardly against the lower ofthe thrust bearings 34 by a nut 38 on the lower end of the positioningshaft 24.

Resilient sealing O-rings 44 are positioned surrounding the positioningshaft 24 at the upper and lower extremities of the central housingportion 12 sealing radially between said shaft and central housingportion preventing fluid flow axially along the positioningshaft betweenthe upper and lower pressure chambers 20 and 22 while still permittingrotation of the positioning shaft relative to the central housingportion. Further, a

similar sealing Q-ring 46 is positioned around the positioning shaft 24upwardly of the upper pressure chamber 20 and the shaft collar 36sealing radially between the positioning shaft and the upper housingportion 14 preventing fluid flow axially along the positioning shaft andupwardly through the upper housing portion 14. Still further, similarsealing O-ririgs 48 are positioned around the central housing portion I2above and below the thrust bearings 34 between the central housingportion and the upper and lower housing portions 14 and I6 preventingfluid flow from the upper and lower pressure chambers 20 and 22 betweenthese housing portions.

Generally opposite first and second housing ports 50 and 52 are formedthrough the central housing portion 12, each communicating with both ofthe upper and lower pressure chambers 20 and 22 as will be hereinafterexplained more in detail. Also, generally opposite third and fourthhousing ports 54 and 56, spaced alternately between the first and secondhousing ports 50 and 52, are formed through the central housing portion12, the third housing port communicating with only the upper pressurechamber 20 and the fourth housing port communicating with only the lowerpressure chamber 22. All of the first through fourth housing ports 50,52, 54 and 56 open into the respective upper and lower pressure chambers20 and 22 axially toward and against the upper and lower rotors 26 and30 so that the rotors are positioned for controlling fluid flow throughthese housing ports, depending on the particular positioning of therotors.

As best seen in FIGS. 6, 7 and 9, the first housing port 50 includes aprimary part 58 extending radially into the central housing portion 12and connected secondary upper and lower parts 60 and 62 extendingaxially through said central housing portion and respectively to theupper and lower pressure chambers 20 and 22, the second housing port 52including the similarly extending primary part 64, secondary upper part66 and secondary lower part 68 Furthermore, as best determined by acomparison of FIGS. 6 and 7, the secondary upper and lower parts 60 and62 of the first housing port 50 are circumferentially offset or atopposite circumferential sides of and communicating with the primarypart 58 of said first housing port, while the secondary upper and lowerparts 66 and 68 of the second housing port 52 are similarlycircumferentially offset at opposite citcumferential sides of theprimary part 64 of said second housing port. As shown in FIG. 9, thesecondary upper parts 60 and 66 of the first and second housing ports 50and 52 are shown in phantom lines and the secondary lower parts 62 and68 thereof are shown in broken lines to indicate such relativecircumferential offset positioning. The result is that the center linesof the secondary upper parts 60 and 66 of the first and second housingports 50 and 52 are circumferentially spaced l communicating with commonsides of the primary parts 58 and 64 of said housing ports asviewed inFIG. 6, and the center lines of the secondary. lower parts 62 and 68 ofthe first and second housing ports 50 and 52 are spaced apart 120 in theopposite circumferential direction and communicate with the oppositesides of the primary parts 58 and 64 of said housing ports as viewed inFIG. 7.

The third housing port 54 extends radially and then axially to the upperpressure chamber20 on right angle coincident center lines as best seenin FIGS. 2 and 6, the fourthhousing port 56 extending similarly to thelower pressure chamber 22 as best seen in FIGS. 2 and 7. The furtherresult, therefore, is that the third housing port 54 opens into theupper pressure chamber 20 with the center line thereof spaced 120between the center lines of the first and second housing ports 50 and-52as shown in FIG. 6, while the fourth housing port 56 opens into thelower pressure chamber. 22 with the center line thereof ofiset 120between the center lines of the first and second housing ports 50 and 52as shownin FIG. 7. Thus, the first, second and third housing ports 50,52 and 54 open axially into the upper pressure chamber ZO'againsttheupper rotor 26 substantially equally circumferentially spaced about thecentral housing portion 12, and the first, second and fourth housingports 50, 52 and 56 open axially into the lower pressure chamber 22against the lower rotor equally circumferentially spaced about thecentral housing portion 12 but circumferentially between said portopenings into the upper pressure chamber.

As shown in FIG. 5, the upper rotor 26 has two ports 70 formed axiallytherethrough withthe center lines of said ports being spaced apart. l20,and as shown in FIG. 8, the lower rotor 30 has two ports 72 formedaxially therethrough with the center lines of said ports spaced 120apart. The upperrotor ports 70 may therefore be positioned alternatelyin communication with the first and third housing ports 50 and 54 or thesecond and third housing ports 52'and 54, and the lower rotor ports 72may be positioned in communication alternately with the first and fourthhousing ports 50 and 56 or the second and fourth housing ports 52 and56. Equally important, however, not only are the upper and lower rotors26 and 30 simultaneously pivotal by pivoting the positioning shaft 24,but the the upper rotor ports 70 are in the opposite circumferentialhalf of the upper rotor from the lower rotor ports 72 in the lowerrotor.

The various ports of the central housing portion 12 and the upper andlower rotors 26 and 30 are therefore positioned in relation to eachother so that the upper pressure chamber 20 can only communicate one ata time with the first and second housing ports 50 and 52 and the lowerpressure chamber 22 can only communicate one at a time with said firstand second housing ports. Furthermore, when the upper pressure chamber20 is in communication with the first housing port 50, the lowerpressure chamber 22 is in communication with the second housing portion52, and when the upper pressure chamber is in communication with thesecond housing port, the lower pressure chamber is in communication withthe first housing port, the two pressure chambers never being incommunication with the same of the first and second housing ports in theparticular arrangement shown. It will also be noted that the 120circumferential spacing of the center lines of both the housing androtor ports taken with the relative sizes of said ports permit allhousing ports to be closed by the upper and lower rotors 26 and 30duringan interval in the movement of said rotors between their alternatecommunicating positions.

As best seen in FIGS. 1, 2 and 9, the positioning shaft 24 projectsupwardly through the upper housing portion 14 with the upper end thereoftelescoped by a positioning cap 74 pivotally overlying the upper housingportion. The positioning cap 74 is secured to the positioning shaft 24by a connecting pin 76, whereby, pivotal movement of the positioning capcauses consequent pivotal movement of the positioning shaft for pivotingthe upper and lower rotors 26 and 30 between their alternate positionsin the manner hereinbefore described. Such alternate positions of theupper and lower rotors 26 and 30 is preferably determined by apositioning pin 78 mounted in the upper housing portion 14 andprojecting upwardly into an arcuate positioning slot80 formed in andopening downwardly of the positioning cap 74, the extremities of thepositioning slot determining the upper and lower rotor alternatepositions. In addition, it is preferred to provide a spring urgedpositioning ball 82 mounted in the upper housing portion 14 for upwardreception in a series of spaced, arcuate, positioning recesses 84 in andopening downwardly of the positioning cap 74, the positioning recessesbeing appropriately spaced for determining the various positions of theupper and lower rotors. I

Referring particularly to FIGS. 3 and 4, in order to provide optimumnoninterflow characteristics of the rotary valve of the presentinvention, unique forms of spool-type seals are arranged in the variousfirst, second, third and fourth housing ports 50, 52, 54 and 56 at theends of these ports against the upper and lower rotors 26 and 30. Thespool-type seal of FIG. 3 is preferably mounted in each of the first,third and fourth housing ports 50, 54 and 56, said seal being arrangedfor providing maximum sealing qualities when fluid is flowing 1 fromthat particular housing port toward the upper'or lower rotor 26 or 30and toward the upper or lower pressure chamber 20 or 22, although acertain amount of sealing is provided by this seal for fluid flow in thereversedirection. The seal of FIG. 4 is mounted in each of the twosecond housing ports 52 and is particularly adapted for sealing fluidwhere fluid flow is from the upper or lower pressure chamber 20 or 22through the upper or'lower rotor 26' or 30 into the central housingportion 12 since the fluid flow in these second housing ports 52 willalways be in this direction in a particular embodiment of rotary valveshown.

Referring more particularly to FIG. 3, a spool-type seal generallyindicated at 86 is received in an annular recess generally indicated at88 of the central housing portion 12 surrounding the end of one branchof the first housing port 50, said recess 88 opening axially endwisetoward, in this particular case, the lower radial surface 29 of theupper rotor 26 and forming a radial annular end surface 90 axiallyspaced from the recess open end and a cylindrical annular wall 92extending axially from said end surface 90 to the recess open end. Asshown, the recess 88 also preferably includes an auxiliary recessportion 94 radially outwardly offset form the main part of recess 88 atthe open end of the first port 50 in the central housing portion 12. Theauxiliary recess portion 94 is likewise annular opening radially intothe first housing port 50 forming a part of the recess cylindrical wall97. and opening endwise toward the upper rotor 26.

The seal 86 includes rigid, annular sealing spool 96 axially movable,preferably slidable, along the recess cylindrical wall 92 with anannular, reduced radial section 98 axially aligned with and axiallymovable in the auxiliary recess portion 94. Furthermore, the reducedradial section 98 of the sealing spool 96 axially abuts the lower radialsurface 28 of the upper rotor 26 while forming a relieved end surfaceI00 around the sealing spool 96. The sealing spool 96 terminates axiallyaway from the upper rotor 26 within the recess 88 axially spaced fromthe recess end surface 90.

The seal 86 further includes an annular, preferably radially flat, guardring 102 in the recess 88 axially adjacent the sealing spool 96, aresilient sealing ring 104 in the recess axially adjacent the guardring, a rigid, annular backing spool 106 in the recess axially adjacentthe sealing ring 104, and an annular spring 108 in the recess axiallybetween the backing spool and the recess end surface 90. The backingspool 106 is axially movable, preferably slidable, along the recesscylindrical wall 92 and has a radially reduced section 110 extendingradially inwardly of and axially along the sealing ring 1114 and theguard ring 102, movably telescoped by the sealing spool 96. The reducedsection 110 of the backing spool 106, therefore, confines the guard ring102 and sealing ring 104 between this reduced section and the recessCylindrical wall 92 as shown.

The guard ring 102 closely slidably abuts the recess cylindrical wall 92to prevent the sealing ring 104 from extruding axially along this guardring and between the sealing spool es and the recess cylindrical wallupon the sealing ring being axially deformed or flattened by fluid flowpressure axially against said sealing ring from between the backingspool 1G6 and the recess cylindrical wall. At the same time, it ispreferred to dimension the sealing ring 104 so that said sealing ringduring said axial flattening will seal tightly against the recesscylindrical wall 92, while exerting lesser radial pressure against theradially reduced section 110 of the backing spool 106 permittingmovement between said backing spool and the sealing spool 96.

The spring 108 is preferably a deformed, washer-type spring reactingaxially between the backing spool 1116 and the recess end surface 90while occupying a minimum axial space of the recess 88. As examples, thespring 108 may be formed of spring steel, and the sealing and backingspools 96 and 11% may be formed of stainless steel, metal beingpreferred partic ularly where high fluid pressures are involved. Theguard ring 102 may be of plastic, such as one of the usual memoryplastics, and the sealing ring 104 may be a usual resilient materialO-ring.

Thus, with the seal 86 of FIG. 3 in the first, third and fourth housingports 50, 54 and 56, fluid flow pressure around the backing spool 106between said backing spool and the recess cylindrical wall 92 willaxially flatten the sealing ring 1114 to seal between said sealing ringand said recess cylindrical wall. This said pressure will exert axialpressure against the sealing spool 96 to cause the reduced radialsection 98 of the sealing 'spool to sealingly abut the particular radialsurface of the upper or lower rotor 26 or 30. With the provision of theaxially reacting spring 1015, such spring will augment this axialabutment, although the reduced radial section 28 of the sealing spool 96will be somewhat axial balanced by fluid pressure against the relievedend surface 11111 of the sealing spool so that excess pivoting force isnot required to pivot the rotors. Although maximum sealing of the seal$6 is obtained where the fluid flow pressure is in the axial directionfrom the particular housing port, it will be appreciated that a certainamount of sealing takes place even with the fluid flow in the reversedirection.

Referring particularly to FIG. 4, a seal generally indicated at 112 ismounted in a recess generally indicated at 116 at the ends of the secondhousing ports 52 in the central housing portion 12, the particularsecond housing port shown being that opening axially against the upperrotor 26. As hereinbefore pointed out, the fluid flow of the secondhousing ports 52 of the particular embodiment of rotary valveillustrated is always from the upper and lower pressure chambers 20 and22 axially into said second housing ports so that the seal 112 isparticularly adapted for such flow. The recess 114 is somewhat similarto that for the seal 86 and, in this case, is annular surrounding theends of the second housing ports 52 opening axially toward the lowerradial surface 28 of the upper rotor 26 forming an annular end surface116 spaced axially from the upper rotor 26 and an annular, cylindricalwall 116 extending axially from said end surface to said open end.

The seal 112 includes a rigid, annular sealing spool 1211 having a mainsection 122 primarily within the recess 114i and movable, preferablyslidable, axially along the recess cylindrical wall 118. The sealingspool main section 122 is axially spaced from the recess end surface 116and has a reduced radial section 12d extending axially from said mainsection 122 axially past the recess end surface within the secondhousing port 52, although closely radially adjacent said end surfaceinner extremity as shown. The sealing spool 120 further has a reducedradial section 126 preferably axially aligned with the reduced radialsection 124, but projecting axially from the main section 122 toward andabutting the lower surface 28 of the upper rotor 26 and forming arelieved end surface 128 on said sealing spoolmain section 122.

The seal 112 further includes an axially reacting spring 130 axiallybetween the sealing spool main section 122 and the recess end surface116, a rigid backup ring 132 axially adjacent said spring, a resilientsealing ring 134 axially adjacent said backup ring, and a guard ring 136axially between said sealing ring and the recess end surface 116. All ofthe spring 130, backup ring 132, sealing ring 134 and guard ring 136 areradially confined by the sealing spool reduced radial section 124between said reduced radial section and the recess cylindrical wall 118,the backup ring 132 being axially movable, preferably slidable, betweensaid sealing spool reduced radial section 124 and the recess cylindricalwall 18 and the guard ring 136 at least closely slidably abutting thesealing spool reduced radial section 124. The sealing spool and backupring may again be formed of stainless steel, the washer-type spring1300f spring steel and the guard ring 136 of memory plastic, with thesealing ring 134 a usual O-ring.

With the seal 112 and the fluid flow pressure axially from the upperpressure chamber 20 into the second housing port 52, therefore, fluidpressure will be exerted outwardly around the sealing spool main section122, the spring 130 and the backing ring 132 to axially flatten thesealing ring 134 which is preferably dimensioned to exert maximum radialpressure against the reduced radial section 124 of the sealing spool andlesser radial pressure against the recess cylindrical wall 118permitting movement of the sealing spool 120 within the recess 114. Theguard ring 136 prevents axial extrusion of the sealing ring 134 alongthe reduced radial section 124 of the sealing spool 120, and the springacts axially against both the sealing spool main section 122 and thebackup ring 132. The spring pressure axially against the sealing spoolmain section 122 forces the reduced radial section 126 into abutmentwith the upper rotor 26, while the relieved end surface 128 of thesealing spool 120 somewhat balances this axial sealing pressurepermitting ease of movement of the rotors.

In operation of the particular embodiment of rotary valve illustrated,assume that the first housing port 50 is connected to a source of fluidunder pressure for receiving fluid into the rotary valve, the secondhousing port 52 is connected back to said fluid source for directingexhaust fluid to said source, and the third and fourth housing ports 54and 56 are connected to opposite ends of a double acting, fluid actuatedcylinder. With the upper and lower rotors 26 and 30 in the positionsshown in FIG. 5 and 8, the fluid will flow into and through the firsthousing port 50, upwardly through one of the upper rotor ports 70 intothe upper pressure chamber 21), downwardly through the other of theupper rotor ports 70 into the third housing port 54, and through saidthird housing port to one end of the fluid cylinder driving the fluidcylinder in one direction. At the same time, fluid will exhaust from theopposite end of the fluid cylinder into and through the fourth housingport 56 downwardly through one of the lower rotor ports 72 into thelower pressure chamber 22, upwardly through the other of the lower rotorports 72 into the second housing port 52, and through and from saidsecond housing port ounvardly exhausting back to the source of fluid.

Pivoting the positioning shaft 24 to pivot the upper and lower rotors 26and 30 simultaneously to their alternate positions will axially alignthe upper rotor ports 70 with the second and third housing ports 52 and$4, and the lower rotor ports 72 with the first and fourth housing ports50 and 56, thereby reversing the fluid flow through the upper and lowerpressure chambers 20 and 22, and reversing the fluid flow through thethird and fourth housing ports 54 and 56. This reverses the direction ofdriving of the fluid cylinder and although the direction of fluid flowin the third and fourth housing ports 54 and 56 is reversed, the firsthousing port 50 remains an inlet port and the second housing port 52remains an exhaust or ,L outlet port. Furthermore, in the, pivotalmovement of the upper and lower rotors 26 and 30, it will be noted thatall of the housing ports 50, 52, 54 and 56 of the central housingportion 12 are completely closed by the upper and lower rotors during aninterval of such pivotal movement so as to prevent interflow betweensaid ports and maintain pressure within the upper and lower. pressurechambers 20 and 22, the unique seals 86 and 112 augmenting thisnoninterflow characteristic and providing optimum results.

Thus, according to the principles of the present invention, a rotaryvalve is provided having a unique construction including two pressurechambers 20 and 22 incorporated in a minimumsize valve housing whichpermits the formation of a true, noninterflow rotary valve. Theprovision of the separate pressure chambers and 22 permits properspacing of the various housing and rotor ports required for suchinterflow characteristics without the necessity of either increasing theoverall rotary valve size or reducing the capacity thereof for a givenvalve size. Where optimum noninterflow characteristics are desired, andparticularly where relatively high fluid pressures are encountered,unique forms of spool-type seals 96 and 112 are incorporated in therotary valve providing maximum sealing while still permitting relativeease of rotary valve operation and switching between the variouspositions thereof, said unique seal constructions being advantageouslyusable in other fluid transmitting'devices and particularly whererelatively movable members are encountered.

I claim:

1. In a rotary valve, the combination of: a housing including axiallyspaced upper and lower portions separated by a central portion; apressure chamber formed in each of 'said housing upper and lower ortionsopening axially against said housing central portion; a rotor pivotalbetween at least two positions in each of said upper and lower pressurechambers axially adjacent said housing central portiom spaced first,second, third and fourth ports through said housing central portion andinto certain of said pressure chambers, said first and second portsopening into each of said pressure chambers against said rotors thereof,said third port opening into said upper pressure chamber against saidupper chamber rotor and being free of opening into said lower pressurechamber, said fourth port openinginto said lower pressure chamberagainst said lower chamber rotor andbeing free of opening into saidupper pressure chamber; two particularly positioned ports through eachof said rotors communicating axially between said housing centralportion and the respective of said pressure chambers,

\ said ports of said upper chamber rotor communicating through saidupper chamber rotor and said upper pressure chamber between at leastsaid first and third housing central portion ports when said upperchamber rotor is in one of said positions and between at least saidsecond and third housing central portion ports when said upper chamberrotor is in the other of saidpositions, said ports of said lower chamberrotor communicating through said lower chamber rotor and said lowerpressure chamber between at least said second and fourth housing centralportion ports when said lower chamber rotor is in one of said positionsand between at least said first and fourth housing central portion portswhen said lower chamber rotor is in the other of said positions; andpositioning means for pivoting said rotors between their two positions.

2. A rotary valve as defined in claim 1 in which said rotors and saidhousing central portion are constructed and said ports thereofrespectively arranged so that each of said rotors seals off one of saidports of said housing central portion in each of said rotor positions.

3. A rotary valve as defined in claim 1 in which said positioning meansis operably connected'to each of said rotors for simultaneously pivotingsaid rotors between each of said rotors two positions.

4. A rotary valve as defined in claim 1 in which said positioning meansis operably connected to both of said rotors for simultaneously pivotingsaid rotors between each rotor two positions, said positioning'meansoperable connection placing both of said rotors simultaneously in theirone position and simultaneously in their other position.

5. A rotary valve as defined in claim 1 in which each of said rotors isconstructedand the ports thereof arranged sealing off at least one ofsaid housing central portion ports previously communicating with atleast one of said rotor ports prior to said at least one rotor portscommunicating with another of said housing central portion ports duringsaid pivotal movements of said rotors by said positioning; means.

6. A rotary valve as defined in claim 1 in which said rotors areconstructed and said ports thereof arranged sealing off all of saidhousing central portion ports during an interval of rotorpivotalmovement by said positioning means between said rotor two positions.

7. A rotary valve as defined in claim 1 in which said rotor positioningmeans includes a shaft extending axially through said housing centralportion pivotal relative to said housing central portion and secured toeach of said rotors for simultaneously pivoting said rotors duringpivotal movement of said shaft.

8. A rotary valve as defined in claim 1 in which annular sealing meansis positioned in certain of said housing central portion portsresiliently urged abutting radial surfaces of said rotor for forming afluid seal axially between said housing central portion and said rotorswhile permitting pivotal movements of said rotors relative to saidhousing central portion by said rotor positioning means.

9. A rotary valve as defined in claim 1 in which each of said rotors isconstructed and said ports thereof arranged for pivotal movement of saidrotors through substantially l20 between said rotor two positions.

10. A rotary valve as defined in claim 1 in which said rotor positioningmeans is operably connected to said rotors for simultaneously pivotingsaid rotors between said rotor two positions, said rotors each being insaid one position simultaneously and in, said other positionsimultaneously; and in which said two ports of each rotor are on centersspaced substantially apart, said ports of one rotor being positioned ina one half of that particular rotor opposite from the one half of theother of said rotors containing said other rotors two ports.

11. A rotary valve as defined in claim 1 in which sealing means ispositioned in an annular recess around certain of said housing centralportion ports, said recess opening axially endwise toward a radialsurface of one of said rotors, said recess forming a radial annular endsurface in said housing central portion axially spaced from said recessopen end and a cylindrical annular wall from said recess end surface tosaid recess open end; and in which said sealing means includes a rigidannular sealing spool in said housing central portion recess axiallymovable along said recess cylindrical wall and axially abutting saidrotor radial surface, a resilient sealing ring in said recess axiallyadjacent said sealing spool, a rigid annular backing spool in saidrecess axially movable along said recess cylindrical wall and axiallyadjacent said sealing ring, said backing spool having a radially reducedsection extending axially along an inner side of said sealing ringconfining said sealing ring radially between said reducedsection andsaid recess cylindrical wall, said reduced section being movablytelescoped by said sealing spool, fluid under pressure flowing from saidhousing central portion port to a rotor port exerting axial pressureagainst said backing spool and sealing ring to axially flatten saidsealing ring sealing against said recess cylindrical wall and force saidsealing spool axially against said rotor radial surface.

12. A rotary valve as defined in claim 1 in which sealing meansisposition ed in an annular recess around certain of said housingcentral portion ports, said recess opening axially endwise toward arotor radial surface, said housing central portion recess forming aradial annular end surface in said housing central portion axiallyspaced from said recess open end and a cylindrical annular wall fromsaid recess end surface to said recess open end; and in which saidsealing means includes a rigid annular sealing spool in said housingcentral portion recess, said sealing spool having a main section axiallymovable along said recess cylindrical wall axially spaced from saidrecess end surface and axially abutting said rotor radial surface, saidsealing spool having a radially reduced section spaced radially inwardof said recess cylindrical wall extending axially from said main sectionto beyond said recess end surface within said housing central portionport and movable radially adjacent said recess end surface, axiallyreacting spring means axially adjacent said sealing spool main sectionradially confined between said sealing spool reduced section and saidrecess cylindrical wall, a rigid backup ring axially adjacent saidspring means and axially movable along and radially between said sealingspool reduced section and said recess cylindrical wall, a resilientsealing ring axially between said backup ring and said recess endsurface radially confined between said sealing spool reduced section andsaid recess cylindrical wall, the combination of said spring meansreacting axially between said sealing spool and backup ring and fluidunder pressure flowing through said housing central portion port urgingsaid sealing spool axially against said rotor radial surface and axiallyflattening said sealing ring to seal against said recess cylindricalwall.

13. A rotary valve as defined in claim 1 in which said housing centralportion and said rotors are constructed and said poi ts thereof arrangedso that said rotors each totally cover one of said housing centralportion ports during an interval of pivoting of said rotors betweentheir two positions; and in which sealing means is positioned betweencertain of said housing central portion ports and each of said rotorsfor providing a fluid seal between said housing central portion and saidrotors while permitting said pivotal movements of said rotors by saidpositioning rneans.

14. In a rotary valve, the combination of: a housing having spacedpressure chambers formed therein with a portion of said housingtherebetween; a rotor pivotal between certain positions in each of saidpressure chambers adjacent said housing portion; at least three portsthrough said housing por tion and opening into each of said spacedpressure chambers against said chamber rotors; at least two portsthrough each of said chamber rotors located alignable with certain ofsaid housing portion ports in certain of said positions of said rotorsforming communications between said certain housing portion ports andsaid chambers during said alignment; and positioning means for pivotingsaid chamber rotors between said certain positions.

15. A rotary valve as defined in claim 14 in which said two rotor portsare positioned relative to said three housing portion ports so that saidtwo rotor ports of each rotor are alignable with a different combinationof said housing portion ports in each of two positions of a particularrotor, each of said rotors sealing off all three of its housing portionports during a part of said rotor pivoting between said rotor twopositions.

1. In a rotary valve, the combination of: a housing including axiallyspaced upper and lower portions separated by a central portion; apressure chamber formed in each of said housing upper and lower portionsopening axially against said housing central portion; a rotor pivotalbetween at least two positions in each of said upper and lower pressurechambers axially adjacent said housing central portion; spaced first,second, third and fourth ports through said housing central portion andinto certain of said pressure chambers, said first and second portsopening into each of said pressure chambers against said rotors thereof,said third port opening into said upper pressure chamber against saidupper chamber rotor and being free of opening into said lower pressurechamber, said fourth port opening into said lower pressure chamberagainst said lower chamber rotor and being free of opening into saidupper pressure chamber; two particularly positioned ports through eachof said rotors communicating axially between said housing centralportion and the respective of said pressure chambers, said ports of saidupper chamber rotor communicating through said upper chamber rotor andsaid upper pressure chamber between at least said first and thirdhousing central portion ports when said upper chamber rotor is in one ofsaid positions and between at least said second and third housingcentral portion ports when said upper chamber rotor is in the other ofsaid positions, said ports of said lower chamber rotor communicatingthrough said lower chamber rotor and said lower pressure chamber betweenat least said second and fourth housing central portion ports when saidlower chamber rotor is in one of said positions and between at leastsaid first and fourth housing central portion ports when said lowerchamber rotor is in the other of said positions; and positioning meansfor pivoting said rotors between their two positions.
 2. A rotary valveas defined in claim 1 in which said rotors and said housing centralportion are constructed and said ports thereof respectively arranged sothat each of said rotors seals off one of said ports of said housingcentral portion in each of said rotor positions.
 3. A rotary valve asdefined in claim 1 in which said positioning means is operably connectedto each of said rotors for simultaneously pivoting said rotors betweeneach of said rotors two positions.
 4. A rotary valve as defined in claim1 in which said positioning means is operably connected to both of saidrotors for simultaneously pivoting said rotors between each rotor twopositions, said positioning means operable connection placing both ofsaid rotors simultaneously in their one position and simultaneously intheir other position.
 5. A rotary valve as defined in claim 1 in whicheach of said rotors is constructed anD the ports thereof arrangedsealing off at least one of said housing central portion portspreviously communicating with at least one of said rotor ports prior tosaid at least one rotor ports communicating with another of said housingcentral portion ports during said pivotal movements of said rotors bysaid positioning means.
 6. A rotary valve as defined in claim 1 in whichsaid rotors are constructed and said ports thereof arranged sealing offall of said housing central portion ports during an interval of rotorpivotal movement by said positioning means between said rotor twopositions.
 7. A rotary valve as defined in claim 1 in which said rotorpositioning means includes a shaft extending axially through saidhousing central portion pivotal relative to said housing central portionand secured to each of said rotors for simultaneously pivoting saidrotors during pivotal movement of said shaft.
 8. A rotary valve asdefined in claim 1 in which annular sealing means is positioned incertain of said housing central portion ports resiliently urged abuttingradial surfaces of said rotor for forming a fluid seal axially betweensaid housing central portion and said rotors while permitting pivotalmovements of said rotors relative to said housing central portion bysaid rotor positioning means.
 9. A rotary valve as defined in claim 1 inwhich each of said rotors is constructed and said ports thereof arrangedfor pivotal movement of said rotors through substantially 120* betweensaid rotor two positions.
 10. A rotary valve as defined in claim 1 inwhich said rotor positioning means is operably connected to said rotorsfor simultaneously pivoting said rotors between said rotor twopositions, said rotors each being in said one position simultaneouslyand in said other position simultaneously; and in which said two portsof each rotor are on centers spaced substantially 120* apart, said portsof one rotor being positioned in a one half of that particular rotoropposite from the one half of the other of said rotors containing saidother rotors two ports.
 11. A rotary valve as defined in claim 1 inwhich sealing means is positioned in an annular recess around certain ofsaid housing central portion ports, said recess opening axially endwisetoward a radial surface of one of said rotors, said recess forming aradial annular end surface in said housing central portion axiallyspaced from said recess open end and a cylindrical annular wall fromsaid recess end surface to said recess open end; and in which saidsealing means includes a rigid annular sealing spool in said housingcentral portion recess axially movable along said recess cylindricalwall and axially abutting said rotor radial surface, a resilient sealingring in said recess axially adjacent said sealing spool, a rigid annularbacking spool in said recess axially movable along said recesscylindrical wall and axially adjacent said sealing ring, said backingspool having a radially reduced section extending axially along an innerside of said sealing ring confining said sealing ring radially betweensaid reduced section and said recess cylindrical wall, said reducedsection being movably telescoped by said sealing spool, fluid underpressure flowing from said housing central portion port to a rotor portexerting axial pressure against said backing spool and sealing ring toaxially flatten said sealing ring sealing against said recesscylindrical wall and force said sealing spool axially against said rotorradial surface.
 12. A rotary valve as defined in claim 1 in whichsealing means is positioned in an annular recess around certain of saidhousing central portion ports, said recess opening axially endwisetoward a rotor radial surface, said housing central portion recessforming a radial annular end surface in said housing central portionaxially spaced from said recess open end and a cylindrical annular wallfrom said recess end surface to said recess open end; and in which Saidsealing means includes a rigid annular sealing spool in said housingcentral portion recess, said sealing spool having a main section axiallymovable along said recess cylindrical wall axially spaced from saidrecess end surface and axially abutting said rotor radial surface, saidsealing spool having a radially reduced section spaced radially inwardof said recess cylindrical wall extending axially from said main sectionto beyond said recess end surface within said housing central portionport and movable radially adjacent said recess end surface, axiallyreacting spring means axially adjacent said sealing spool main sectionradially confined between said sealing spool reduced section and saidrecess cylindrical wall, a rigid backup ring axially adjacent saidspring means and axially movable along and radially between said sealingspool reduced section and said recess cylindrical wall, a resilientsealing ring axially between said backup ring and said recess endsurface radially confined between said sealing spool reduced section andsaid recess cylindrical wall, the combination of said spring meansreacting axially between said sealing spool and backup ring and fluidunder pressure flowing through said housing central portion port urgingsaid sealing spool axially against said rotor radial surface and axiallyflattening said sealing ring to seal against said recess cylindricalwall.
 13. A rotary valve as defined in claim 1 in which said housingcentral portion and said rotors are constructed and said ports thereofarranged so that said rotors each totally cover one of said housingcentral portion ports during an interval of pivoting of said rotorsbetween their two positions; and in which sealing means is positionedbetween certain of said housing central portion ports and each of saidrotors for providing a fluid seal between said housing central portionand said rotors while permitting said pivotal movements of said rotorsby said positioning means.
 14. In a rotary valve, the combination of: ahousing having spaced pressure chambers formed therein with a portion ofsaid housing therebetween; a rotor pivotal between certain positions ineach of said pressure chambers adjacent said housing portion; at leastthree ports through said housing portion and opening into each of saidspaced pressure chambers against said chamber rotors; at least two portsthrough each of said chamber rotors located alignable with certain ofsaid housing portion ports in certain of said positions of said rotorsforming communications between said certain housing portion ports andsaid chambers during said alignment; and positioning means for pivotingsaid chamber rotors between said certain positions.
 15. A rotary valveas defined in claim 14 in which said two rotor ports are positionedrelative to said three housing portion ports so that said two rotorports of each rotor are alignable with a different combination of saidhousing portion ports in each of two positions of a particular rotor,each of said rotors sealing off all three of its housing portion portsduring a part of said rotor pivoting between said rotor two positions.